You can just copy and paste directly over, but that leaves you with a single item that can't be edited. Or you could copy and paste important items. It also made text slightly blurry.
Don't quote me on this, as my memory is a bit fuzzy, but you might be able to copy and paste them into normal Appleworks docs and then open them that way and still have all the separate items clickable. All my normal text docs were just drag and drop onto the icon in the dock to create a newer version.
But because my docs started in 2001ish, many were over ten years old and in desperate need of a total overhaul. That's when I just decided to redo every document in the new Pages. I don't use hyperlinks so that isn't a problem for me, but I was able to re-create all my docs and not only improve the idea behind them, but make them look a lot better as well. Plus using tags in the new OS was a revelation for organising the 500 plus docs I have.